Casein glue



I06. COMPOSITIONS,

COATING OR PLASTIC.

Patented Oct. 26, 1926.

UNITED STATES txata HENRY L. PRES'IHOLDT, F MINNEAPOLIS, MINNESOTA.

CASEIN GLUE.

No Drawing.

Parts.

Casein 50 to 75 Sodium silicate 2 to 2 ITri-sodium phosphate 3to15- Sodium sulphite 3to 18 Calcium oxide 6to Magnesium oxide 10 to The above noted substances are com- 25 mingled in dry or powder form and are sold in that condition. When the composition is to he used, it will be introduced into water -Q to form an emulsion. and it is then. of course,

that the chemical reactions that develop the adhesive qualities of the composition, will take place. After these reactions have taken place, the composition may be mixed with Application filed April 17, 1922. Serial No. 554,202.

paints or other coating substances or it may be applied in the form of an emulsion. I'Vhen desired, the color pigments may be added to the dry composition.

The colloids of the casein are brought into aqueous solution by the use of the following chemicals: trisodium phosphate, sodium sulphite, and calcium oxide. Calcium oxide unites with car-e111. forming an insoluble caseinate of lime which imparts to the glue a wa erproot quality. Using calcium oxide alone. without the addition of magnesium oxide, would make the glue unworkable, because of the liquid characteristic becoming quickly gelatinous. Magnesium oxide delays this process. Sodium silicate is added for the purpose of reducing the cost.

hat I claim is:

An adhesive coating made in accordance with the following formula:

Parts.

Casein 50 to 75 Sodium s'licate 2 to 10 Tri-F'odium phosphate 3 to 15 Sodium sulphitc 3 to 18 Calcium oxide 6 to 15 Magnesium oxide -1O to 25 In testimony whereof I affix my signature.

HENRY L. PRESTHOLDT. 

